!Fishermen's Guild Member Lanosco:

You've obtained all of the Essence of Wind I need to make the bait. Please accept this as a token of my appreciation.
 This will increase your chances of finding lost treasure, but how often you actually land your catch will depend on your skill.

Your fishing skill should be exactly level 8 to obtain the optimum performance from this bait. 
If you're not level 8, you might consider giving to bait to someone who is. Remember, bring anything you recover to me unopened!